1. Field of the Invention
The present invention relates to a printing device, printing system and printing method for printing desired images onto a printing medium, such as fabric, for example, through combined use of screen printing and ink-jet printing.
2. Description of the Related Art
One conventional method for printing images on fabric, such as a T-shirt, for example, is screen printing wherein ink is coated onto a fabric by means of a screen plate on which an image is formed. Since screen printing uses a screen plate, productivity is high, but when printing color images, or the like, a plurality of screen plates must be fabricated. A further method is ink-jet printing wherein ink is emitted directly onto the fabric by means of an ink emitting head. Ink-jet printing of this kind enables highly complex multi-colored printing to be carried out readily, but it takes a long time to printing large surface areas, such as background images, or the like.
Therefore, in recent years, it has been proposed that screen printing and ink-jet printing be used in combination. For example, Japanese Patent No. 3,218,274 discloses a textile printing device which combines a plate-based printing device comprising a screen plate, and a plate-less printing device based on an ink-jet method. After a color design and positioning marks have been printed onto the fabric by means of the plate-based printing section, the fabric is then conveyed to the plate-less printing section, where full color printing is carried out by means of ink-jet printing. In the plate-based printing section, a plurality of screen plates are arranged in parallel fashion, in line with a conveyor belt which transports the fabric. In the plate-less printing section, on the other hand, the positioning marks on the fabric are detected by reading means, and the screen printing image and the ink-jet printing image are made to coincide in position on the basis of these marks.
Moreover, Japanese Patent Application Laid-Open No. 2002-154246 discloses a method wherein, when printing onto a fabric, such as a T-shirt, by means of ink-jet printing, a pre-treatment liquid is coated only onto the region of the fabric that is to be printed, by means of a screen printing method, or the like. The fabric is set on the screen frame and the pre-treatment liquid is coated onto it, whereupon the fabric is set in a printing tray, this tray is installed in an ink-jet printing device, and ink-jet printing is performed. When setting the pre-treated fabric in the printing tray, the operator performs the positional alignment in such a manner that the pre-treated portion and the upper plate of the tray coincide in position.
However, in the device according to Japanese Patent No. 3,218,274, in order to align the positions of the screen printing image and the ink-jet printing image, positioning marks are printed onto the fabric in the plate-based printing section, and these positioning marks on the fabric are detected by reading means in the plate-less printing section. Therefore, special positioning marks and reading means, and the like, are required, and a problem arises in that the configuration of the textile printing device, and the functions thereof, become complicated. Moreover, by arranging a plurality of screen plates in parallel, in line with the direction of travel of a conveyor belt, a problem is created in that overall textile printing device becomes large in size.
Furthermore, in the device according to Japanese Patent Application Laid-Open No. 2002-154246, when setting the pre-treated fabric in the printing tray, the operator must align the positions of the pre-treated section and the upper plate of the tray, in order that they coincide. Therefore, and particularly in cases where an image has been printed in the pre-treatment stage, the operator must pay very careful attention to aligning the positions in order that this first image coincides exactly with the ink-jet printing image to be printed subsequently. Therefore, a problem arises in that the workability deteriorates, and device operability also deteriorates.